1. Field of the Invention
This invention relates generally to an extracorporeal circulation support system coupled to the blood circulation, and more particularly to an extracorporeal circulation support apparatus which directly vents the left ventricle.
2. Background of the Invention
Each year extracorporeal circulation support permits over 500,000 patients worldwide with disabling heart disease to undergo therapeutic cardiac operations. The primary goals of extracorporeal circulation support for heart surgery are, (i) to provide life-support functions, (ii) a motionless decompressed heart, (iii) a dry bloodless field of view for the surgeon, and (iv) adequate myocardial protection.
One method of extracorporeal support includes a basic heart-lung life-support system. Oxygen-poor blood is diverted from the venous circulation of the patient and transported to the heartlung machine where reoxygenation occurs, carbon dioxide is discarded and heat regulation, warming or cooling, is accomplished. This processed blood is then perfused into the patient""s arterial circulation for distribution throughout the entire body to nourish and maintain viability of the vital organs. Although current venous diversion and arterial perfusion methods can be combined with other measures to effectively isolate the heart for cardiac surgery, they are associated with disadvantages and limitations which contribute significantly to patient morbidity, mortality, and health care costs. Another method may involve using a left ventricle assist system to channel blood from the left ventricle into aortic circulation.
In order to perform coronary artery bypass, valve operations and other complex delicate surgical procedures on the heart, it is desirable to establish a resting, non-beating, non-distended state. This condition, along with a dry bloodless field, is ideal for safe manipulation and suturing of cardiac structures. It also contributes to decreased metabolic cardiac energy demands while promoting preservation of cellular functions. This non-beating state is accomplished by delivery of various methods including but not limited to delivery of a cardioplegia solution to the coronary circulation.
There are several methods of controlling distension, decompression or venting, and improved visibility of the heart during heart surgery. These include but are not limited to, (i) insertion of a catheter via the left atrium or a pulmonary vein that is directed across the mitral valve so that its openings at the top are positioned within the left ventricular chamber for venting of blood, (ii) inserting a catheter directly into the apex, of the left ventricular muscle with its openings at the tip positioned within the left ventricular chamber for venting of blood, (iii) placement of a catheter in the isolated segment of the ascending aorta for antegrade cardioplegia delivery that can be alternatively switched to a suction source to accomplish aortic root venting (decompression) but not left ventricular decompression (venting), and (iv) inserting a catheter across the aortic valve into the left ventricle to remove blood from the left ventricle and return it back into the arterial circulations These methods have several disadvantages including but not limited to requiring major sternotomy or thoracotomy.
Major invasive chest incisions are often associated with a higher incidence of morbidity including, but not limited to, intraoperative and post-operative bleeding, resulting in the likelihood of increased blood transfusion requirements, returns to surgery for re-exploration to control hemorrhage, longer healing and recovery times, pulmonary complications (such as lung collapse and pneumonia), catastrophic wound infection (mediastinitis), extensive scarring and adhesions, mechanical wound instability and disruption (dehiscence), chronic incisional pain, peripheral nerve and musculoskeletal dysfunction syndromes.
Developing a system with features that avoids surgical maneuvers, instrumentation and devices known to be associated with increased morbidity and mortality, while maintaining the conditions necessary to perform various cardiac interventions, is desirable. Such improvements have the likelihood of resulting in a favorable impact on patient care, quality of life, and health care costs.
Although peripherally inserted catheters of the prior art avoid direct cardiac trauma and can be placed without a major invasive chest incision (sternotomy or thoracotomy), they do not establish the condition of total extracorporeal circulation support.
It is thus desirable to develop an extracorporeal circulation support system coupled to the blood circulation which directly removes blood from the left ventricle. It is farther desirable to provide a method for directly venting the left ventricle.
Accordingly, an object of the present invention is to provide an extacorporeal circulation support system that occludes the aorta and directly vents the left ventricle.
Another object of the present invention is to provide an extracorporeal circulation support system with a vent lumen that directly vents the left ventricle.
A further object of the present invention is to provide an extracorporeal circulation support system coupled to the blood circulation and directly vents the left ventricle.
Still another object of the present invention is to provide a method for directly venting the left ventricle.
These and other objects of the invention are provided in an extracorporeal support system coupled to the blood circulation. An extacorporeal support apparatus and an arterial circulation support catheter are provided. The arterial circulation support catheter includes a blood lumen with a proximal end coupled to the extracorporeal support apparatus and a distal end inserted into the blood circulation. A vent lumen has a distal end that crosses the aortic valve into the left ventricle and provides direct venting of the left ventricle through the vent lumen. An arterial circulation support catheter occluding member is positioned in an interior or an exterior of the arterial circulation support catheter. A venous circulation support catheter includes a blood lumen with a proximal end coupled to the extracorporeal support apparatus and a distal end inserted into the blood circulation. A venous circulation support catheter occluding member is included and positioned in an interior or at an exterior of the venous circulation support catheter. The venous circulation support catheter occluding member occludes the superior vena cava and the inferior vena cava.
In another embodiment a method for venting the left ventricle of the heart is disclosed. An extracorporeal circulation support system is provided and includes an extracorporeal support apparatus, a venous circulation support catheter, an arterial circulation support catheter and a vent lumen. The arterial circulation support catheter and venous circulation support catheter are introduced into the blood circulation. A vent lumen distal end is positioned in the left ventricle, and the left ventricle is directly vented through the vent lumen.
An arterial circulation support catheter occluding member lumen can be coupled to the arterial circulation support catheter occluding member and positioned in the arterial circulation support catheter. The arterial circulation support occluding member can be slideably positioned in the blood lumen or in the arterial circulatory support occluding member lumen. The arterial circulation support catheter occluding member can be one or more clamps or balloons.
A venous circulation support catheter occluding member lumen can be coupled to the venous circulation support catheter occluding member and positioned in the venous circulation support catheter. The venous circulation support catheter occluding member can be slideably positioned in the venous circulation support catheter blood lumen or in the venous circulation support catheter occluding member lumen.
The arterial circulation support catheter may include an infusion lumen with a distal end that introduces an infusion medium into the aortic root. The infusion lumen may be positioned in the interior of the arterial circulation support catheter at the exterior of the arterial circulation support catheter, in the blood lumens adjacent to the blood lumen or in the arterial circulation support catheter adjacent to the blood lumen.
The venous circulation support catheter may also include an infusion lumen that introduces an infusion medium into the venous circulation. The infusion lumen can be positioned in the interior of the venous circulation support catheter, at the exterior of the venous circulation support catheter, in the blood lumen or in the venous circulation support catheter adjacent to the blood lumen. Inclusion of the infusion lumen permits the introduction of an infusion medium into the venous circulation and may also vent mediums from the venous circulation and/or the right heart either simultaneously or at alternate times.
An interventional lumen, for the introduction of a diagnostic or therapeutic device into the blood circulation, may be positioned in an interior or exterior of the arterial circulation support catheter or in the blood lumen.